Switch-board for electric circuits



(No Model.)

P. BLAKE.

SWITCH BOARD TCR ELECTRIC CIRCUITS. No. 249,574. Patented Nov. 15,1881.

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UNITED STATES PATENT OFFICE.

SWITCH-BOARD FOR ELECTRIC CIRCUITS.

SPECIFICATION forming part of Letters Patent N'o. 249,574, datedNovember 15, 1881.

Application tiled August 22, 1881. (No model.) y

To all whom it may concern:

Be it known that I, FRANCIS BLAKE, of Weston, in the State ofMassachusetts, have invented an Improvement in Commutators for ElectricCircuits, of which the following is a specification.

The invention consists in the combination, with a pile ot' plat-es ofmetal and hard rubber or other insulating material put togetheralternately, of a number of smaller metallic plates, one :for each ofthe electric circuitsbetween which connections are to be made, thesmaller plates secured to one of tbe large insulatingplates,and apeg-hole in and through each smaller plate extending also through allthe large plates.

The invention consists, further, in a peg adapted to make connectionsbetween two of several insulated metallic plates placed in a pile, andtwo only.

The invention consists, further, in the coinbination,withthecommutatorherein described,

of several pairs of pegs, also herein described,

each pair of pegs adapted to be used with any and all the line-plates ofthe commutator, but with only one and the same connecting-plate.

ln the drawings, Figure l isa plan of a commutator constructed accordingto my invention, showing also several pegs inserted therein. Fig. 2 is asection taken on line a: of Fig. 1, and accordingly showing two pairs ofpegs adapted to be used in the commutator, each pair to make aconnection between any two line-plates by means of a particularconnecting-plate, as will hereinafter be described.

In the coinmutator shown the smaller metallic plates are numbered from lto 25, the

latter number being the number of electric cir-vr cuits for which thecom mutator shown is adapt'- ed, and in the practical operation of theconimutator each of these smaller plates thus numberedis connected inany-suitable manner with a line or circuit designated by the samenumber. These smaller plates are known as lineplates.77

The larger metallic plates are lettered A,B, C, D, and E, there beingtive of them in the commutatorshown. Theyareplacedoneabove another, asshown, alternating with insulating plates of the same dimensions. Theyare fastened together by clamping-screws s at their corners, thesescrews passing through insulating-sleeves. (Not shown.) The largemetallic plates A, B, C, D, and E are used for and known asconnecting-plates, since any one of them may be used to make electricalconnection between any two line-plates,it being only necessary toconnect both line-plates between which a connection is desired with thesame connectin g-plate.

A hole bored through each line-plate and extending through all theinsulated connectingplates beneath allows a connection to be madebetween any line-plate and any connectingplate by means of a wire or pegof suitable length and shape inserted in the hole.

A peg adapted to connect any one ot' the line-plates with theconnecting-plate B is shown in section at Fig. 2. The peg, as well asthe plate, is marked B, to facilitate the practical operation, as willhereinafter appear. A peg suitable for making the same connection isalso shown in elevation at Fig. 2, and bears the ysame mark, B. Thesepegsv B have each, as shown, a flange near the head, which, when the pegis fully inserted in a hole in the commutator,is in contact with theline-plate, and they have also, as shown, a flangcat the entering end,which comes in contact with the connectin g-platc B when the peg isfully inserted in a hole.

Both the holes and the pegs are tapered for the more easy insertion ofthe pegs in the holes. The flanges of the pegs are of the thickness ot'the connecting-plates. The insulating-plates may be of any suitablethickness and of any suitable material, and, as is obvious, air may beused, in part, as an insulator. The small /line-plates.are'screwed tothe outer insulatingplate, as shown. At Fig. 2 two other pegs (marked E)are shown, which are adapted to be used for making connection betweentwo line-platesby means ofconnecting-plateE; and it is obvious thatsuitable pegs may be used with any of the connecting-plates for makingconnection between any two line-plates, and,k

further, that pegs adapted to be used with one connecting-plate can beused with no other connecting-plate. In practice, accordingly, theoperator will have a single pair of pegs for each connecting-plate.Keeping each pair in a place by itself, he can readily make a connec-Ico tion between any two line-pIates by inserting any pair of pegs notin use in the holes which pass through the said two line-plates.

I have devised means by which this commutator can be used in connectionwith signaling apparatus located at a central station and operated froma distance at the same time it is used for making connections betweendifferent electric circuits; but such devices will form thesubject-matterot' an application for a separate patent.

I here claiml. A number ot' metallic plates and a number ofinsulating-plates of substantially the same dimensions7 alternatingin aplle,in combination with a number of smaller plates, one for each oftheelectric circuits between which connections are to be made,substantially as described, a peg-hole in and through each smallermetallic plate extending also through all the large plates, whethermetallic or insulating, for the purpose specified.

2. A metallic peg with two anges,substan tially as described, whereby itis adapted to make connections between two of several insulated metallicplates placed in a pile, and two only, for the purpose specified.

3. The combination7 with large insulated connecting-plates and smallerline-plates, perforated, as described, of several pairs of contact-pegs,the contact portions of the said pegs being at equal distances apart inpegs of the same pair, but at unequal distances apartin pegs ofdifferent pairs, whereby each pair of pegs may be used with any and allthe lineplates, but with only one and the same connecting-plate, allsubstantially as described, for the purpose specilied.

FRANCIS BLAKE.

Witnesses:

W. W. SWAN, FRANCIS H. SWAN.

